| 摘要 |
A process is provided for operating a three-way catalyst that contains an oxygen storage component, that has a minimum and a maximum filling degree for oxygen and that is located in the exhaust gas line of an internal combustion engine. The air/fuel mixture supplied to the engine is varied in such a way that the filling degree of the oxygen storage component in the catalyst is held within a set-point interval between the minimum and maximum filling degree. According to this process, in order to regulate the air/fuel mixture, migration of the filling degree out of the set-point interval is checked in a test phase in such a way that the filling degree is increased or lowered relative to the instantaneous value (initial value) by short-term enrichment or reduction in richness of the air/fuel mixture supplied to the engine by a certain amount and immediately returned to the initial value by a short-term opposing change in the air/fuel mixture (lean/rich pulse sequence or rich/lean pulse sequence). In the case of a breakthrough of lean or rich exhaust gas through the catalyst during the test phase, the air/fuel mixture is enriched or reduced in richness in order to correct the filling degree, wherein the amount by which the filling degree during the test phase is increased or decreased is such that no breakthrough of lean or rich exhaust gas takes place through the catalyst when the filling degree of the oxygen storage component is within the set-point interval.
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